Measurements of transfer coefficients for¹³⁷Cs,⁶⁰Co,⁵⁴Mn,²²Na,¹³¹I and^95mTc from feed into milk and beef

Summary

The transfer in cattle of the radionuclides¹³⁷Cs,⁶⁰Co,⁵⁴Mn,²²Na,¹³¹I and^95mTc was studied experimentally to determine transfer coefficients from feed to milk and meat. Special interest was kept on normal feeding and maintenance conditions used in Germany. The radio-nuclides were incorporated into fodder plants through root uptake and thus available in a chemical form resulting from the contamination of agricultural soil. This permitted realistic simulation of the soil-plant-animal food chain. The equilibrium transfer coefficients for milk were calculated to be²²Na: 0.016±0.002 d/l,⁶⁰Co: ≤0.0002 d/l,⁵⁴Mn: ≤0.0005 d/l, and¹³⁷CS : 0.0022±0.0002 d/l. The equilibrium transfer coefficients for meat were calculated to be²²Na: 0.01±0.002 d/kg,⁶⁰Co: ≤0.00013 d/kg,⁵⁴Mn : ≤0.0005 d/kg, and¹³⁷Cs: 0.0062±0.0006 d/kg. A single dose of¹³¹I was orally administered three times in the chemical form of iodide. Models were applied to obtain parameters for a quantitative description of the iodine metabolism. The equilibrium transfer factor for¹³¹I in this chemical form to milk was calculated to be 0.009±0.0014 d/l. For^95mTc only an upper limit of the transfer factor of 1.7 · 10⁻⁴ d/l could be estimated because of the small amount of radioactivity available.